Production of lubricating oils

ABSTRACT

A three-stage, wholly catalytic process for the production of lubricating oil comprises the steps of hydrogenation to improve viscosity index and reduce sulphur content, catalytic dewaxing to reduce pour point and hydrogenation over a halogen containing catalyst to improve viscosity index without increasing the pour point. The optimum conditions for the first stage are those giving a first stage product sulphur content of 0.1 to 0.2 percent wt. The catalyst may be one or more group VI or VII hydrogenating metals on a refractory oxide. The second stage catalyst is preferably platinum group metal incorporated with an alkali metal deficient mordenite. The third stage catalyst may be as for the first catalyst with 1-10 percent wt. halogen, preferably fluorine.

United States Patent Bennett et al.

l l PRODUCTION OF LUBRlCATlNG OILS [75} Inventors: Robert Neil Bennett. Engleficld Green; Brian James Oswald, Cove near Farnborough; Terence Norman Thurlow, New Haw. all of England [73] Assignee: The British Petroleum Company Limited. London. England [22] Filed: Jan. 30, I974 [21] Appl. No: 437.974

l30| Foreign Application Priority Data Feb. 8. W73 United Kingdom 6214/73 [52] US. Cl 208/59; 208/18 |5l| Int. Cl Cl0g 37/02 [58] Field of Search 208/18. 59 57 [56] References Cited UNITED STATES PATENTS 1654.133 4/[972 Olson 208/59 3.663.423 5/[972 Bennett et al. 208/59 fflfld. .90 00- 79% 65% Q 5m- /Vfl- I45] Apr. 29, 1975 SJMJKX 9/]973 Bryson et all 208/59 Primary E.\'amincrHerbert Levine Almrney. Agcnl. or FirmMorgan, Finnegan, Durham & Pine [57] ABSTRACT A three-stage. wholly catalytic process for the production of lubricating oil comprises the steps of hydrogenation to improve viscosity index and reduce sulphur content, catalytic dewaxing to reduce pour point and hydrogenation over a halogen containing catalyst to improve viscosity index without increasing the pour point. The optimum conditions for the first stage are those giving a first stage product sulphur content of 0.l to 0.2 percent wt, The catalyst may be one or more group VI or Vll hydrogenating metals on a refractory oxide. The second stage catalyst is preferably platinum group metal incorporated with an alkali metal deficient mordenite. The third stage catalyst may he as for the first catalyst with ll0 percent wt, halogen. preferably fluorine.

8 Claims, 1 Drawing Figure PP00.//475 m ,4?- L906 PRODL'CTION OF Ll'BRICATlNG ()ILS This invention relates to the production of lubricating oils by a wholly catalytic route without the use of solvents.

lt is well known that. in lubricating oil production. the requirements of high viscosity index and low pour point conflict Aromatics and ring compounds which have to be removed or converted to improve \iscosity index have low pour points. The waxes which have to be removed to improve pour points have high viscosity indexes. The situation is further complicated by the fact that lubricating oil fractions contain mixed cyclic paraffinic compounds (eg. aromatic or naphthenic rings with paraffinic side chains) having intermediate viscosity indexes and pour points.

In practice. the established route of solvent extrac tion of aromatics and solvent dewaxing provides a satisfactory solution at moderate levels of \iscosity index and pour point. Very high viscosity indexes or very low pour points are. however. difficult to achieve with solvents and there are also other practical and economic drawbacks to solvent processes. Considerable research effort has. therefore. been expended in recent years on hydrocatalytic processes as replacements for one or both ofthe solvent steps. A wholly catalytic route is. for example. described and claimed in US. Pat. No. 3.ho3.-123. ln that patent a wholly catalytic process for the production of lubricating oils from a petroleum feedstock boiling above 350C without the use of solents for aromatic and wax removal comprises the steps of passing the oil over a catalyst comprising one or more hydrogenating components selected from Groups Vla and VIII of the Periodic Table on a refractory oxide support together with hydrogen at a temper ature of from 343 to 454C and a pressure of from 70 to 210 bars gauge to give a material of reduced aro matic content and improved viscosity index and also a catalyst comprising one or more hydrogenating components selected from Groups Vla and VIII of the Periodic Table incorporated with a crystalline mordenite of reduced alkali-metal content together with hydrogen at a temperature of from 232 to 510C and a pressure of 7 to Zl bars gauge to give a material of reduced wax content and improved pour point. said steps of viscosity index improvement and catalytic dewaxing being carried out in either order, and recovering a lubricating oil fraction ofboth improved viscosity index and improved pour point.

It is now been found that a wholly catalytic process can be further improved by using three stages. and using a particular catalyst in the third stage. In the third stage viscosity index can be improved without adversely affecting pour point.

According to the present invention a wholly catalytic process for the production of lubricating oils from a pctroleum feedstock boiling above 350C without the use of solvents for aromatic and wax removal comprises the steps of passing the oil over a catalyst comprising one or more hydrogenating components selected from Groups VIa and VIII of the Periodic Table on a refractory oxide support together with hydrogen at a temper ature of from 343 to 454C and a pressure of 70 to 210 bars gauge. then over a catalyst comprising one or more hydrogenating components selected from Groups Vla and VIII of the Periodic Table incorporated with a crystalline mordenite of reduced alkali metal content together with hydrogen at a temperature of from 250 to 500C and a pressure of from 7 to 210 bars gauge. and then over a catalyst comprising one or more hydrogenating components selected from Groups Vlu and VIII of the Periodic Table on a refractory oxide support containing 1 to l0 percent wt of halogen together with hydrogen at a temperature of from 300 to 450C and a pressure of from 30 to 210 bars gauge and recovering a product of decreased pour point and increased viscosity index as compared with the feedstock.

The feedstock to the process is preferably a vaccum distillate fraction boiling within the range 350- 600C. Since lubricating oils are marketed in several grades with relatively narrow boiling ranges. distillation to give relatively narrow boiling range cuts is required at some stage. In the present invention. a wide boiling range cut may be used as feedstock and distillation into narrower cuts given after the first. second or third hydrocatalytic treatments or distillation may take place before the hydrocatalytie treatments and individual cuts may be hydrotreated. The former route has the advantage of avoiding blocked operation but the latter route has the advantage that optimum hydrogenating conditions may be chosen for each cut.

The support may be a single oxide e.g. alumina. which is preferred. or a mixed oxide cg. silica-alumina. Suitable proportions may be 10- 100 percent wt Al: O; and 0 percent SiO, Halogen is preferably absent from this first stage catalyst.

The Group \"la metals are chromium. molybdenum and tungsten. and the preferred Group Vlll metals are the iron group metals. i.e. iron. cobalt. and nickel. These components are normally used in the form of ox ides or sulphides. lf platinum group metals are used they are normally present as metals or metal sulphides. The amounts of the hydrogenating components may be Group \'|a metals 3 15''; \\t texpressed as metal) lron Group metals 1 15; \\t Platimum Group metals (Ll 5; \\t 1'') Preferred hydrogenating components are from 2 25 percent wt of molybdenum (expressed as metal but present as oxide or sulphide) and l l5 percent wt of cobalt and/or nickel (again expressed as metal but present as oxide or sulphide). Another suitable combination may be tungsten-nickel-sulphide with from (H percent to 30.0 percent \vt tungsten and (H percent to 20.0 percent wt nickel expressed as metal.

The precise level of V.l. improvement required can be determined by experiment and a large improvement may be unnecessary. In fact. as described hereafter. desulphurisation is the more significant reaction. In practice feedstocks with V.l.s of 45 to 65. Pour points of 30 to 50C and sulphur contents of 2 percent to 4 percent wt can be treated to give products boiling above 370C with V.l.s of 60 to 100. pour points of 30 to 50C and sulphur contents of 0.00] to 0.5 percent wt. The other main process conditions can be chosen from the following ranges:

Space velocity H;- gas rate moval of H- S and NH and. if desired. removal of product boiling below the boiling point of the initial feed stock In practice it has been found that optimum results are achieved. in terms of maximum yield of desired final product if the first stage severity is such that the sulphur content of the product passing to the catalytic de waxing stage is from 0.1 to 0.2 percent wt. Higher sulphur contents lower the activity of the deway'ing cata lyst. thereby reducing yield for a given pour point. Lower sulphur contents do not give a large improve ment in the activity of the dewaxing catalyst and require a higher severity and hence lower yield in the first stage.

The catalytic dcwaxing stage may he essentially as described in UK Pat. No. l.l3b.223 and the earlier UK Pat. Nos. 1088.933 and 1134.014. Thus the catalyst may be from 0.] to 5 percent of a platinum group metal. particularly platinum itself. incorporated with a crystalline mordenite having an alkali metal content of less than I lwt. particularly a decationised mordenitc. The preferred SiO- Al 0:, ratio of the mordenite is from l4:l to 501i. The other main process conditions may be chosen from:

Space \elocity H gas rate In practice products from the first stage with. as indicated above. V.l.'s of from an to I00. pour points of from 30 to 50C and sulphur contents of 0.00] to 0.5 percent wt can he catalytically dewaxed to give prod ucts boiling above 370C having V.l.s of from 30 to 90, pour points of 48 to +9C and sulphur contents of U.ll0l to 0.5 percent wt.

Second stage product work up may be as for the other stages. The was is catalytically cracked to light paraffinic hydrocarbons up to C particularly C and C, paraffins. which may he recovered as useful byproducts.

The product from the first two stages. while of suitable pour point may he rather low in viscosity index and the object of the third stage is to improve the viscosity index without adversely affecting the pour point. i.e.. the increase in pour point is preferably nil and at most 6C. As pre\iously stated. the second stage products may have \"l's of from 30 to 90 and these can be increased to from 75 to I while keeping the pour point within the range 48 to +9C The hydrogenating components and the support may be as for the first stage catalyst.

The halogen may be chlorine or fluorine particularly the latter. and it is this component which provides the key to the process. The halogen content is preferably from 0.5 to 70 percent wt and may he added in known manner. Thus it may be added by impregnating the sup port with a solution of a halogen acid. eg hydrofluoric acid, or a halide. eg. ammonium fluoride. or by passing vapours of an organic halogen compound over the sup port under conditions which decompose the compound. Suitable compounds are fluorinated derivatives ofC C, aliphatic hydrocarbons. e.g. carbon tetrafluoride.

The other main process conditions may be chosen from the following ranges.

Space \elocity v'hr 0.l 50 H: gas rate mlcm" I00 2.000

EXAMPLE 1 The feedstock was a straight run distillate lubricating oil fraction from Kuwait crude having a boiling range of 480 to 550C. Portions of it were treated in three stages to improve V.l. and pour point.

The catalyst compositions were First Stage Second Stage LUNG wt nickel oxide 2.589} wt cobalt oxide 9.29? wt molybdenum o\idc 1H"? wt silica 8h, l0} wt alumina Z m lg surface area II 5779 wt platinum balance mordenite with It 755; wt sodium The third stage treatment used two catalysts. of co bait and molybedenum oxides on silica-alumina one fluorinated and the other not. The non-fluorinated catalyst. used for comparative purposes had the following amounts of Co. Mo and Si. expressed as metal the element. but present as oxides. The balance was alumina.

Cobalt i wt l 75 Molybdenum M II 7 Silicon 9; \\t 9.0 Fluorine \\t Nll. Surface area m l Ul The catalyst of the present invention was fluorinated by allowing I00 mls of the CoMo/siliea-alumina to remain in contact with 10 g of NH,F in I00 mls of deionized water for 24 hours. The catalyst was filtered off. dried at C for to hours. and calcined at 550C for 2 hours. It contained 6.l percent wt of fluorine. The process conditions used and the results obtained with the two catalysts are set out in Tables 1 and 2 below. Table shows the results with the comparative nonfluorinated third stage catalyst. and Table 2 the results with the fluorinated third stage catalyst of the present invention TABLE I Feedstock First Stage Second Stage Third Stage Operating conditions Catalyst NiCoMo/alumina Platinum-hydrogen CoMo/silicamordenite alumina Temperature T MK) 40H 3X5 Pressure hars gauge lllt) Hltl IOU Space \elocity v/ /hr LU 1,0 It) H gals rate m"/m L250 R40 84" Inspection data on material boiling ahmc the indicated flash point Kinematic viscosity at 324C e5 2788 79.7(1 H18 67.70

Pour point C |l-l l5 l2 -1 Viscosity lndes 5| X3 70 85 Flash Pmm C 229 I96 213 m5 Sulphur it \\t 3.03 (I421) .23 t).t)ll

Yield wt 87.0 737 92.4

Data on wheat Llc\\i|\ctl material Table 2 Feedstock First Stage Second Stage Third Stage Operating Conditions Catalyst NiCoMo/Alumina Platinum-Hydrogen Fluorinated Mordenile (oMo/Silica-Alumina Temperature C 387 375 394 Pressure hats gauge [U3 ltl] Ill] Space velocity v/v/hr HI IA) (1.5

H- gas rate m/m" I250 840 R40 Inspection data on material hoiling ahove the indicated flash point Kinematic Viscosity at 3X(' es 278% lllh.7 l5).7 43.54

Pour Point "C -l8 lR 9: -Q Viscosity lndey SI 76 59 94 Flash Point 229 I 3 227 I88 Sulphur Content '1 wt 31)} (L27 0.27 "U055 Yield '4 wt R7,] 717 69.8

+ Data on sulwnl \lC\\lt\t!ll material EXAMPLE 2 A three stage process according to Example 1 using the same feedstock and a fluorinated third stage catalyst was carried out. using a CoMo/alumina catalyst in the first stage instead of a NiCoMo/alumina. The catalyst composition was Process conditions and product inspection data for the three stages are shown in Table 3 below.

Table 3 Feedstock First Stage Second Stage Third Stage Operating Conditions Catalyst CoMolAlumina Platinum-Hydrogen Fluorinated Mordenite CoMo/Silica-Alumina Temperature 38X 385 385 Pressure I03 1113 H1} Space \elocit 1.0 l,l1 (1.5

H: gas rate 1.25 840 8-1-1) Inspection data on material boiling above the indicated flash point Kinematic Viscosity at 38C 278,8 7644 130.3 46.24

cS Pour Point C ll l5 -l5 Viscosity Index 81 87 (13 )5 Flash Point 12*) I99 210 I88 Sulphur Content 09 wt 3.03 (H157 (1H1 Yield '7: t 8349 oil] 69.7

+ Data on solvent d|:\\a\ctl matcrlal EXAMPLE 3 The pressures. space velocities and gas rates in all The accompanying graph shows the changes in product viscosity and viscosity index when operating according to Table 2 of Example 1 but varying the seven ity of the first stage to give products with sulphur contents of (120 and (1.27 percent wt respectively Each product was then catalytically dewaxed to a pour point of l 2C. and hydrogenated over the fluorinated catalyst to increase the V.l. while keeping the -l 2C pour point. The 0.18 percent wt S content first stage product was hydrogenated to 95 V.l. and the 0.26 percent wt S content product was given two different treatments to 93 and 105 V.l.

The graph shows that the viscosity/viscosity index relationship was not affected by the variation in sulphur content. The overall yield was however, different in the two cases and a further series of experiments was carried out according to Table 3 of of Example 2 to de termine the optimum first stage product sulphur content for maximum yield. 4 runs were carried out to give first stage products with sulphur contents of 0.0 l 6. 00- 59. (1.12. and 0.24 percent wt respectively which were then catalytically dewaxed. The first three products were also hydrogenated over the fluorinated catalyst The results are set out in Table 4 below.

three stages were the same as in Table 3, variations in product quality being obtained by temperature variation, except that, with the first stage product of 0.24 percent wt S content the second stage space velocity had to be reduced to v/v/hr to give a pour point of It will be seen that similar products were obtained in the three complete runs but that the yield increased with increasing first stage product sulphur content. Although the yields in the first two stages of the fourth run were slightly higher than for the third run, it was found that the required second stage product pour point in the fourth run could only be obtained by re ducing the space velocity The fourth run product was. therefore. not treated in the third stage and by extrap olation the optimum first stage product sulphur content for maximum yield was found to be 0.15 percent wtv We claim:

1. A wholly catalytic process for the production of lubricating oils from a petroleum feedstock boiling above 350C without the use of solvents for aromatic and wax removal comprising the steps of passing the oil over a catalyst comprising one or more hydrogenating components selected from Groups Vla and VIII of the Table 4 First stage product Sulphur content 71 wt (1.1116 (H159 (1.12 [1,24 Yield "/5 t 77 K5 8) 9| Second stage product Pour Point "C |5 l2 |K l2 Yield on original feed "ll wt 5U 61 66 b8 Thll'tl stage Temperature C 379.5 384.5 399 Final Product Data Kinematic viscosit at 38C CS 43.11 46.2] 41.8) Viscosity Index 96 94 94 Pour point l 5 l 2 Yield on original feed fi wt 32 44 45 Periodic Table on a refractory oxide support together with hydrogen at a temperature of from 343 to 454C and a pressure of 70 to 210 liars gauge then over a catalyst comprising one or more hydrogenating components selected from Groups \'la and VIII of the Periodic Table incorporated with a crystalline mordenite of reduced alkali metal content together with hydrogen at a temperature of from 250 to 500C and a pressure of from 7 to 2 l l ars gauge. and then over a catalyst comprising one or more hydrogenating components selected from (iroups Vlu and VIII of the Periodic Table on a refractory oxide support containing l to l0 per' cent wt of halogen together with hydrogen at a temper ature of from 200 to 450C and a pressure of from to Zlll hars gauge and recovering a product of decreased pour point and increased \iscosity index as compared with the feedstock.

2. A process as claimed in claim 1 wherein the feedstock is a vacuum distillate fraction boiling within the range 350 to 600C.

3. A process as claimed in claim I wherein the first and third stage catalysts contain. as hydrogenating components 25 percent wt of a Group Vlu metal and l l5 percent wt ofone or more iron group metals both by weight of total catalyst and. as support. 10 to 100 percent wt alumina and 0 percent wt silica. both by weight of the support.

4. A process as claimed in claim I. wherein the first stage is operated to give a first stage product sulphur content of 0.1 to 0.2 percent wt.

5. A process as claimed in claim 1 wherein the second stage catalyst contains from 0.1 to 5 percent wt of a platinum group metal incorporated with a crystalline mordenite having an alkali metal content of less than 2 percent wt,

6. A process as claimed in claim 5 wherein the mordenite is a decationised mordenite having a SiO .:Al. O; ratio of from 14:1 to 50:1.

7. A process as claimed in claim I wherein the halogen of the third stage catalyst is fluorinev 8. A process as claimed in claim I wherein the halo gen content of the third stage catalyst is from 3 to 7 

1. A WHOLLY CATALYTIC PROCESS FOR THE PRODUCTION OF LUBRICATING OILS FROM A PETROLEUM FEEDSTOCK BOILING ABOVE 350*C WITHOUT THE USE OF SOLVENTS FOR AROMATIC AND WAX REMOVAL COMPRISING THE STEPS OF PASSING THE OIL OVER A CATALYST COMPRISING ONE OR MORE HYDROGENATING COMPONENTS SELECTED FROM GROUPS VIA AND VIII OF THE PERIODIC TABLE ON A REFRACTORY OXIDE SUPPORT TOGETHER WITH HYDROGEN AT A TEMPERATURE OF FROM 343* TO 454*C AND A PRESSURE OF 70 TO 210 BARS GAUGE, THEN OVER A CATALYST COMPRISING ONE OR MORE HYDROGENATING COMPONENTS SELECTED FROM GROUPS VIA AND VIII OF THE PERIODIC TABLE INCORPORATED WITH A CRYSTALLINE MORDENITE OF REDUCED ALKALI METAL CONTENT TOGETHER WITH HYDROGEN AT A TEMPERATURE OF FROM 250* TO 500*C AND A PRESSURE OF FROM 7 TO 210 BARS GAUGE, AND THEN OVER A CATALYST COMPRISING ONE OR MORE HYDROGENATING COMPONENTS SELECTED FROM GROUPS VIA AND VIII OF THE PERIODIC TABLE ON A REFRACTORY OXIDE SUPPORT
 2. A process as claimed in claim 1 wherein the feedstock is a vacuum distillate fraction boiling within the range 350* to 600*C.
 3. A process as claimed in claim 1 wherein the first and third stage catalysts contain, as hydrogenating components, 2 - 25 percent wt of a Group VIa metal and 1 - 15 percent wt of one or more iron group metals both by weight of total catalyst and, as support, 10 to 100 percent wt alumina and 0 - 90 percent wt silica, both by weight of the support.
 4. A process as claimed in claim 1, wherein the first stAge is operated to give a first stage product sulphur content of 0.1 to 0.2 percent wt.
 5. A process as claimed in claim 1 wherein the second stage catalyst contains from 0.1 to 5 percent wt of a platinum group metal incorporated with a crystalline mordenite having an alkali metal content of less than 2 percent wt.
 6. A process as claimed in claim 5 wherein the mordenite is a decationised mordenite having a SiO2:Al2 O3 ratio of from 14:1 to 50:1.
 7. A process as claimed in claim 1 wherein the halogen of the third stage catalyst is fluorine.
 8. A process as claimed in claim 1 wherein the halogen content of the third stage catalyst is from 3 to 7 percent wt. 